My Vivoactive 4s appears to have died completely after a few hours of activity in the sun on a very hot day. :-( I've tried all the usual fixes: cleaning the contacts, connecting it to charge and doing the 30-second button press, etc., but nothing has worked. Once in a while, when I have it connected to a USB port via the charging cable, it will seem to revive briefly - see attached photos for examples - but it always goes dead again after a few seconds.
Is this likely to be a battery failure? I've had the watch for about three years. Before this failure, the battery seemed to be in good shape; it held a charge well and all functions seemed to work correctly. If replacing the battery might help, does anyone have a model number, specifications or link for a suitable replacement battery? (I saw a post about a replacement battery for the VA 4, but not for the VA 4s.) Or is it more likely that some other component(s) might be at fault?
I could pay $140 for a refurbished replacement watch, but I'm wondering if I could just fix it myself instead. I'm sure opening the case would void any remaining warranty, but I'm reasonably handy and have fixed several laptops, phones and other small electronics by opening them up and replacing components, and I'm willing to assume responsibility if I completely wreck my existing watch. If anyone can share any relevant specs, ideas or tips, I'd appreciate them. Thanks!
(At other times, it's also displayed a summary of the "accept/delete" screen for my last recorded workout. I just haven't been able to get a photo of that screen before it disappears.)